We often forget how skin deep the atmosphere of our planet
really is. The picture below will serve as an illustration :

Into this waver-thin layer of air we add every year over
3 billion metric tons of carbon.
( See CO2 Cycle ).

Studies from ice cores taken from 3 km below the surface of Antarctica
show that CO2 is about 30% higher than any time during the last 650,000 years; and the
rates of increase today are absolutely exceptional: for CO2, 200 times faster than during the last 650,000 years.

Regardless of model predictions it is safe to assume that such an
increase of yearly emission must have some impact and that
at some time this impact will become irreversible.

In 2004 Science magazine conducted a review of 928 papers published between 1993 and 2003 in refereed scientific journals. They found that none of the 928 papers disagreed with the current scientific consensus that human activity is significantly affecting global climate change.